Nutless Bolt With Break-Off Actuator for Reusable Locking
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Solution Overview
Problem
Existing nutless bolts, such as those described in International publication no. WO 2006/108245, require destruction for removal, which is inefficient and not suitable for applications where reusability is desired.
Innovation Solution
A nutless bolt design featuring a shaft with a locking mechanism operated by an actuator that breaks into two portions upon application of a tensile force, allowing the bolt to be locked and unlocked without destruction, using a stop to prevent the bolt from falling through a hole and a sleeve to maintain the locking mechanism in place.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the locking mechanism is made permanent and secure, then the fastening reliability is improved, but the removal complexity increases requiring destruction of the bolt
Solution Approach 1:
The actuator is divided into two separate portions: a first portion that remains in the body to maintain the locking mechanism in the locked position, and a second portion that can be removed. This segmentation allows the locking function to remain permanent and reliable while enabling easy removal by extracting only the second portion of the actuator.
2Stability of the object's composition
If the actuator remains intact after locking, then the locking mechanism stability is improved, but the removal time increases requiring bolt destruction
Solution Approach 1:
The actuator is segmented into two portions where the first portion stabilizes the locking mechanism in the locked position while the second portion is designed for easy removal. This allows the locking mechanism to maintain stability without requiring the entire actuator to remain intact, significantly reducing removal time.
Solution Approach 2:
The second portion of the actuator is extracted or removed from the body after the locking mechanism is engaged. This extraction allows the locking mechanism to remain stable and functional while enabling quick removal of the bolt by taking out only the necessary actuator portion.
3Strength
If a traditional rivet design is used, then the fastening strength is improved, but the reusability is lost as rivets cannot be removed
Solution Approach 1:
The bolt design incorporates a dynamic locking mechanism that can transition between locked and unlocked states. The actuator with its two portions enables the locking mechanism to be engaged for strong fastening and then disengaged by removing the second portion of the actuator, allowing the bolt to be reused unlike traditional static rivets.
Solution Approach 2:
The second portion of the actuator is discarded or removed after use, while the first portion remains in the body to maintain the locking mechanism. This allows the bolt to be recovered and reused, providing adaptability and versatility that traditional rivets lack.
Data Source
Figure 1~3
AI summary
A nutless bolt (10) for fastening a wear plate (12) to a structure (14) comprises a body (16) having a shaft (18) and a stop (20) coupled to the shaft (18). Shaft (18) is dimensioned to pass through a hole (22) in structure (14) while stop (20) is configured to stop the body (16) from falling wholly into or through the hole (22), and to engage with the wear surface plate. An axial bore (24) is formed in body (16) and houses locking balls (58) and a rod (28). The body (16) also has radial channels along which the balls (58) can roll. The rod (28) has a tapered portion (70) which increases in outer diameter from a first location (L1) to a second location (L2). In use the balls (58) are initially at the first location (L1) on the rod (28) and partially within respective channels (56). Pulling the rod (28) in an up-hole direction results in the rod (58) moving in a radial outward direction as they roll along the tapered portion (70) to the location (L2). The balls now lie partially outside of the body (16) locking the bolt (10) in the hole (22). Applying additional pulling force on the rod increases tension in the rod to intentionally cause a controlled break or separation of the rod into a first portion (72) that is withdrawn from the bore and a second portion (62) that remains in the bore and bearing against the balls (58).